This is the third competing renewal for our Training in Virology T32 program, which is a combination of previously separate Pre- and Postdoctoral training grants that were merged into a single program during the last competitive renewal. Our Training in Virology Program uses the facilities of the University of Pennsylvania (Medical, Dental, and Vet Schools), the Wistar Institute, and the Children's Hospital of Philadelphia, all of which share a compact, contiguous campus. Among our 34 NIH-funded virologists, a select group of 19 are trainers on this program, with 7 trainers being women or minorities. For the past 15 years, this program has supported 5 predoctoral and 3 postdoctoral trainees per year. Over the past funding period, this Virology T32 supported 14 predoctoral trainees (8 men, 6 women, 3 under-represented minorities) and 9 postdoctoral fellows (3 men, 6 women, 2 under-represented minorities). Thus, 52% of our trainees have been women, and 22% have been under-represented minorities. These 23 trainees worked in the labs of 19 different trainers. Our training program takes a direct and active role in minority recruitment - seven of our trainers have attended the ABRCMS or SACNAS meetings over the past three years, and a willingness to attend these meetings is a requirement for being a trainer on this grant. Many of our past trainees now hold positions in academics and industry, where they continue to study virology. At present, there are 39 postdoctoral (19 being T32-eligible) and 31 predoctoral (29 being T32-eligible) trainees being mentored by trainers associated with this virology T32, with most of these trainees studying topics that are directly relevant to our Virology Training Program. Thus, appointment to this T32 is highly competitive. Since our last competing renewal, our graduate program has nearly tripled in size, the fraction of our postdoctoral fellows who are T32-eligible has increased dramatically (to nearly 50%) in part through our program-specific recruitment efforts, the number of minority students entering our program has increased dramatically, new faculty have been hired, and research facilities expanded or renewed. However, given the current NIH funding situation coupled with our desire to remain highly selective, we propose to maintain our Training in Virology Program at its current size of 5 predoctoral and 3 postdoctoral trainees per year. Importantly, Penn continues to provide direct and tangible institutional commitment to training in the biomedical sciences by (among other things) funding the Biomedical Postdoctoral Programs office and by supported predoctoral trainees for their first 21 months of graduate school. Our trainers direct numerous program-specific training activities, from a very well attended weekly virology seminar series in which our trainees present their work, to updating our virology curriculum, instituting a new program to emphasize biostatistics and quantitative methods, and coordinating our very pro-active minority recruiting efforts. Our interactive and highly collaborative group of virologists, documented by numerous joint publications, lab meetings and grants, provide an unusually broad training environment for our outstanding group of pre- and postdoctoral trainees.